Lipase‐catalyzed aza‐Michael addition of amines to acrylates in supercritical carbon dioxide

Abstract

AbstractBACKGROUNDAza‐Michael addition, a powerful method for the synthesis of β‐amino carbonyl derivatives, has been extensively studied in organic chemistry. In this study, the efficient and chemoselective aza‐Michael addition of amines to acrylates catalyzed by lipase in supercritical carbon dioxide (scCO2) was reported for the first time.RESULTSUnder the optimal conditions [amine (1 mmol), acrylate (1 mmol), novozym 435 (20 mg), 40 °C, scCO2 (25 mL, 10 MPa)], the corresponding Michael adducts of amines to acrylates were exclusively obtained in high yields (60–93%) for a short reaction time (1 h). No aminolysis was observed when scCO2 was used as reaction medium. Moreover, novozym 435 showed high reusability in scCO2 for aza‐Michael addition.CONCLUSIONThe excellent chemoselectivity and reusability of novozym 435 in scCO2 indicate the method's great potential for practical application. © 2019 Society of Chemical Industry